Getting off the Ground: MLB’s Fly Ball Revolution

The fly-ball revolution is in full swing. The number of hits classed as fly-balls (a hit with a launch angle between 10-25 degrees) is on an upward trend, as is the average launch angle of all hits in the league. Home run totals are going through the roof and, in an attempt to understand why, Ben Lindbergh and Michael Lichtman concluded in 2017 that the balls used at the elite level are probably “juiced” in some way.

Getting in on the Action

MLB have responded with the announcement that they will introduce controlled conditions for the storage of baseballs, presumably in the hope of creating consistency across all 30 teams. Individual players have seen a massive increase in their run production by adjusting their approach to modify their launch angle. Most notably, Francisco Lindor hit more homers last time out than he had in the previous two years combined, by increasing his average launch angle from 7.7 to 13.7 degrees.

So while it is not a huge surprise that teams have been getting in on the action, there are some teams who have not. The Mets and Twins, with relatively hitter-friendly ballparks, are second and third on the list respectively, but Athletics, Royals, and Padres, who make up the rest of the top five all play in home run-suppressing home parks, so it is a bit more surprising to see them with such high fly-ball percentages.

From Small Ball to Power Hitting

Of those teams in the top five GB/FB rate from last year, only the Twins had a winning season. Although in basic terms you might say that the strategy hasn’t worked, that wouldn’t necessarily be a fair evaluation. The Royals, who, objectively speaking, have declined in the period since their back-to-back World Series trips in 2014-15, are an interesting example. They went from being a 95 win team to an 80 win team in just two seasons, but most visibly because of their pitching and defence. In 2014-15 they allowed 1265 runs, and, in the two years since then, have allowed 1503, representing an 18% increase.

The Royals appear to have consciously changed their run-scoring approach in this period as well. The back-to-back World Series-reaching Royals were a small ball team built with speed and steals. In 2014 they stole 153 bases, the highest total in MLB, but last season they stole just 91, tied with the Marlins for tenth most. What they have been doing since then to get their runs instead is to hit for more power, with their ISO jumping 53 points from .113 to .156 from 2014 to 2017. They seem to have achieved this increase with a proclivity to hit the ball in the air.

Not surprisingly, their increased tendency to hit fly balls has brought with it a whopping increase in home runs. In 2014-15 they hit 234 homers, but in 2016-17 they hit 340 — an increase of 45%. Their Slugging Percentage trended up considerably too, from .376 in 2014 to .420 in 2017. So in spite of their pitching and defence deteriorating, their increases in SLG, HR’s and ISO should have upped their game in terms of scoring runs, right?

Wrong. In those four seasons, the Royals’ run production has basically stayed the same, 2014-15 yielding 1375 runs, and 2016-17 yielding 1377, just two more. Unfortunately, it seems the home runs could do little to help them score runs, as with the third-lowest OBP in the majors last year they couldn’t get men on base to be driven home. So why have the Royals changed the way they score runs? Why have they so wholeheartedly committed themselves to the fly ball revolution?

Chasing the Herd

It could be the herd mentality – the idea that if everyone else is doing it, it must be the right thing to do, and wanting to get the best out of players. But that doesn’t really tally with the Royals, who had seen the benefits of their approach bear fruit in reaching consecutive World Series. It could be that they came to the realisation that home runs are cheaper to foster then batting average, OBP, and steals, and they were faced with the challenge of replacing ageing and/or expensive talent with more affordable options. It could be that they wanted to get the best out of guys like Mike Moustakas and Brandon Moss, both of whom saw increased home run output through greater average launch angle and exit velocity. Most probably it is a combination of all three factors, but clearly it hasn’t worked for them unless you argue that they would have been even worse off relative to 2014-15 if they hadn’t embraced the change.

It will be interesting to see what happens this season in terms of launch angle trends, fly-balls, and home runs. Two teams – the Yankees and Orioles – are projected to break the single season team home run record this season, which would be an astonishing reflection of the current situation. Perhaps some teams might determine that it’s better to hit line drives than fly-balls and tailor their strategy more to the team’s attributes. More likely we will see even more dingers, and, let’s be honest, apart from the pitcher being charged with the earned run, who has a problem with that?